Pixels, display device comprising pixels, and driving method therefor

Abstract

In a pixel, a display device including a pixel, and a method of driving the display device, the pixel includes a first transistor connected to a first power source, a fourth node and a first node, a second transistor connected to a third node, a data line and an i-th first scan line, a third transistor connected to the first node, the fourth node, and an i-th third scan line, a fourth transistor connected to the second node, an initialization voltage, and an i-th second scan line, a first capacitor connected between the third node and the first node, a second capacitor connected between the first node and the second node, and an organic light emitting diode connected between the second node and a second power source, wherein I is a natural number and the third transistor is an N-type transistor.

The invention claimed is: 
     
       1. A pixel comprising:
 a first transistor connected between a first power source and a fourth node, and having a gate electrode connected to a first node; 
 a second transistor connected between a third node and a data line, and turned on in response to a scan signal applied to an i-th first scan line, where i is a natural number; 
 a third transistor connected between the first node and the fourth node, and turned on in response to a scan signal applied to an i-th third scan line, where i is a natural number; 
 a fourth transistor connected between a second node and an initialization voltage, and turned on in response to a scan signal applied to an i-th second scan line, where i is a natural number; 
 an organic light emitting diode connected between the second node and a second power source; 
 a first capacitor connected between the third node and the first node; and 
 a second capacitor connected between the first node to which the gate electrode of the first transistor is connected and the second node to which an anode of the organic light emitting diode is connected, 
 wherein the third transistor is an N-type transistor. 
 
     
     
       2. The pixel of  claim 1 , wherein at least one of the second transistor and the fourth transistor is the N-type transistor. 
     
     
       3. The pixel of  claim 2 , wherein the fourth transistor is the N-type transistor and the i-th second scan line is the same scan line as an (i+1)-th third scan line. 
     
     
       4. The pixel of  claim 2 , wherein the second transistor is the N-type transistor and the i-th first scan line is the same scan line as the i-th third scan line. 
     
     
       5. The pixel of  claim 4 , wherein the fourth transistor is the N-type transistor and the i-th second scan line is the same scan line as an (i+1)-th third scan line. 
     
     
       6. The pixel of  claim 1 , wherein the i-th second scan line is the same scan line as an (i+1)-th first scan line. 
     
     
       7. The pixel of  claim 1 , further comprising:
 a fifth transistor connected between a reference voltage and the third node and turned on in response to a light emission signal applied to a light emission control line; and 
 a sixth transistor connected between the fourth node and the second node and turned on in response to the light emission signal applied to the light emission control line. 
 
     
     
       8. The pixel of  claim 7 , wherein the second transistor and the third transistor are turned on during a first period, the fourth transistor is turned on during a second period subsequent to the first period, and the fifth transistor and the sixth transistor are turned on during an emission period subsequent to the second period. 
     
     
       9. The pixel of  claim 1 , wherein the second transistor and the third transistor are turned on during a first period, and the fourth transistor is turned on during a second period subsequent to the first period. 
     
     
       10. A display device comprising:
 pixels connected to scan lines and data lines; 
 a scan driver supplying scan signals to the scan lines; and 
 a data driver supplying data signals to the data lines, 
 wherein at least one of the pixels which is connected to an i-th horizontal line, where i is a natural number, comprises: 
 a first transistor connected between a first power source and a fourth node, and having a gate electrode connected to a first node; 
 a second transistor connected between a third node and a data line, and turned on in response to a scan signal applied to an i-th first scan line, where i is natural number; 
 a third transistor connected between the first node and the fourth node, and turned on in response to a scan signal applied to an i-th third scan line, where i is a natural number; 
 a fourth transistor connected between a second node and an initialization voltage, and turned on in response to a scan signal applied to an i-th second scan line, where i is a natural number; 
 an organic light emitting diode connected between the second node and a second power source; 
 a first capacitor connected between the third node and the first node; and 
 a second capacitor connected between the first node to which the gate electrode of the first transistor is connected and the second node to which an anode of the organic light emitting diode is connected, and 
 wherein the third transistor is an N-type transistor. 
 
     
     
       11. The display device of  claim 10 , wherein the scan driver supplies a scan signal with one of a first polarity and a second polarity opposite the first polarity to the first to third scan lines. 
     
     
       12. The display device of  claim 11 , wherein at least one of the second transistor and the fourth transistor is the N-type transistor. 
     
     
       13. The display device of  claim 11 , wherein the fourth transistor is the N-type transistor and the i-th second scan line is the same scan line as an (i+1)-th third scan line. 
     
     
       14. The display device of  claim 11 , wherein the second transistor is the N-type transistor and the i-th first scan line is the same scan line as the i-th third scan line. 
     
     
       15. The display device of  claim 14 , wherein the fourth transistor is the N-type transistor and the i-th second scan line is the same scan line as an (i+1)-th third scan line. 
     
     
       16. The display device of  claim 11 , wherein the i-th second scan line is the same scan line as an (i+1)-th first scan line. 
     
     
       17. The display device of  claim 11 , further comprising:
 an emission driver supplying a light emission signal to light emission control lines, 
 wherein the at least one pixel further comprises: 
 a fifth transistor connected between a reference voltage and the third node, and turned on in response to the light emission signal applied to the light emission control line; and 
 a sixth transistor connected between the fourth node and the second node, and turned on in response to the light emission signal applied to the light emission control line. 
 
     
     
       18. The display device of  claim 17 , wherein the scan driver sets a scan signal applied to the first scan line and the third scan line during a first period to a turn-on level, sets a scan signal applied to the second scan line during a second period subsequent to the first period to a turn-on level, and sets the light emission signal to a turn-on level during an emission period subsequent to the second period. 
     
     
       19. The display device of  claim 11 , wherein the scan driver sets a scan signal applied to the first scan line and the third scan line during a first period to a turn-on level and sets a scan signal applied to the second scan line during a second period subsequent to the first period to a turn-on level. 
     
     
       20. A method of driving a display device including a plurality of pixels,
 at least one of the pixels, which is connected to an i-th horizontal line, where i is a natural number, including: 
 a first transistor connected between a first power source and a fourth node, and having a gate electrode connected to a first node; 
 a second transistor connected between a third node and a data line, and turned on in response to a scan signal applied to an i-th first scan line, where i is natural number; 
 a third transistor connected between the first node and the fourth node, and turned on in response to a scan signal applied to an i-th third scan line, where i is integer natural number; 
 a fourth transistor connected between a second node and an initialization voltage, and turned on in response to a scan signal applied to an i-th second scan line, where i is integer natural number; 
 an organic light emitting diode connected between the second node and a second power source; 
 a first capacitor connected between the third node and the first node; and 
 a second capacitor connected between the first node to which the gate electrode of the first transistor is connected and the second node to which an anode of the organic light emitting diode is connected, the method comprising: 
 turning on the second transistor and the third transistor during a first period; and 
 turning on the fourth transistor during a second period subsequent to the first period. 
 
     
     
       21. The method of  claim 20 , wherein the third transistor is an N-type transistor. 
     
     
       22. The method of  claim 20 , wherein the at least one pixel further comprises:
 a fifth transistor connected between a reference voltage and the third node, and turned on in response to the light emission signal applied to the light emission control line; and 
 a sixth transistor connected between the fourth node and the second node, and turned on in response to the light emission signal applied to the light emission control line, the method further comprising: 
 turning on the fifth transistor and the sixth transistor during an emission period subsequent to the second period.